Decoding data streams in a distributed storage network

ABSTRACT

A method begins by a dispersed storage (DS) processing module receiving one or more pairs of coded values and continues with the DS processing module creating a received coded matrix from the one or more pairs of coded values, followed by the generation of a data matrix. When a decode threshold number of pairs of coded values are included in a first plurality of data blocks corresponding to a data stream from the data matrix and the decode threshold number of pairs of coded values are determined to be valid, the decode threshold number of pairs of coded values are decoded. The method continues with the generation of a second data matrix and the data stream is extracted from the second data matrix.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility patent application claims priority pursuant to35 U.S.C. §120 as a continuation-in-part of U.S. Utility applicationSer. No. 14/954,836, entitled “TIME ALIGNED TRANSMISSION OF CONCURRENTLYCODED DATA STREAMS”, filed Nov. 30, 2015, which is a continuation ofU.S. Utility patent application Ser. No. 13/565,636, entitled “TIMEALIGNED TRANSMISSION OF CONCURRENTLY CODED DATA STREAMS”, filed Aug. 2,2012, now U.S. Pat. No. 9,213,742 issued on Dec. 15, 2015, which claimspriority pursuant to 35 U.S.C. §119(e) to U.S. Provisional ApplicationNo. 61/531,317, entitled “COMMUNICATING ONE OR MORE DATA STREAMSUTILIZING DISPERSED STORAGE ERROR ENCODING”, filed Sep. 6, 2011, all ofwhich are hereby incorporated herein by reference in their entirety andmade part of the present U.S. Utility patent application for allpurposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION Technical Field of the Invention

This invention relates generally to computing systems and moreparticularly to data storage solutions within such computing systems.

Description of Related Art

Computers are known to communicate, process, and store data. Suchcomputers range from wireless smart phones to data centers that supportmillions of web searches, stock trades, or on-line purchases every day.In general, a computing system generates data and/or manipulates datafrom one form into another. For instance, an image sensor of thecomputing system generates raw picture data and, using an imagecompression program (e.g., JPEG, MPEG, etc.), the computing systemmanipulates the raw picture data into a standardized compressed image.

With continued advances in processing speed and communication speed,computers are capable of processing real time multimedia data forapplications ranging from simple voice communications to streaming highdefinition video. As such, general-purpose information appliances arereplacing purpose-built communications devices (e.g., a telephone). Forexample, smart phones can support telephony communications but they arealso capable of text messaging and accessing the internet to performfunctions including email, web browsing, remote applications access, andmedia communications (e.g., telephony voice, image transfer, musicfiles, video files, real time video streaming. etc.).

Each type of computer is constructed and operates in accordance with oneor more communication, processing, and storage standards. As a result ofstandardization and with advances in technology, more and moreinformation content is being converted into digital formats. Forexample, more digital cameras are now being sold than film cameras, thusproducing more digital pictures. As another example, web-basedprogramming is becoming an alternative to over the air televisionbroadcasts and/or cable broadcasts. As further examples, papers, books,video entertainment, home video, etc. are now being stored digitally,which increases the demand on the storage function of computers.

A typical computer storage system includes one or more memory devicesaligned with the needs of the various operational aspects of thecomputer's processing and communication functions. Generally, theimmediacy of access dictates what type of memory device is used. Forexample, random access memory (RAM) memory can be accessed in any randomorder with a constant response time, thus it is typically used for cachememory and main memory. By contrast, memory device technologies thatrequire physical movement such as magnetic disks, tapes, and opticaldiscs, have a variable response time as the physical movement can takelonger than the data transfer, thus they are typically used forsecondary memory (e.g., hard drive, backup memory, etc.).

A computer's storage system will be compliant with one or more computerstorage standards that include, but are not limited to, network filesystem (NFS), flash file system (FFS), disk file system (DFS), smallcomputer system interface (SCSI), internet small computer systeminterface (iSCSI), file transfer protocol (FTP), and web-baseddistributed authoring and versioning (WebDAV). These standards specifythe data storage format (e.g., files, data objects, data blocks,directories, etc.) and interfacing between the computer's processingfunction and its storage system, which is a primary function of thecomputer's memory controller.

Despite the standardization of the computer and its storage system,memory devices fail; especially commercial grade memory devices thatutilize technologies incorporating physical movement (e.g., a discdrive). For example, it is fairly common for a disc drive to routinelysuffer from bit level corruption and to completely fail after threeyears of use. One solution is to utilize a higher-grade disc drive,which adds significant cost to a computer.

Another solution is to utilize multiple levels of redundant disc drivesto replicate the data into two or more copies. One such redundant driveapproach is called redundant array of independent discs (RAID). In aRAID device, a RAID controller adds parity data to the original databefore storing it across the array. The parity data is calculated fromthe original data such that the failure of a disc will not result in theloss of the original data. For example, RAID 5 uses three discs toprotect data from the failure of a single disc. The parity data, andassociated redundancy overhead data, reduces the storage capacity ofthree independent discs by one third (e.g., n−1=capacity). RAID 6 canrecover from a loss of two discs and requires a minimum of four discswith a storage capacity of n−2.

While RAID addresses the memory device failure issue, it is not withoutits own failure issues that affect its effectiveness, efficiency andsecurity. For instance, as more discs are added to the array, theprobability of a disc failure increases, which increases the demand formaintenance. For example, when a disc fails, it needs to be manuallyreplaced before another disc fails and the data stored in the RAIDdevice is lost. To reduce the risk of data loss, data on a RAID deviceis typically copied on to one or more other RAID devices. While thisaddresses the loss of data issue, it raises a security issue sincemultiple copies of data are available, which increases the chances ofunauthorized access. Further, as the amount of data being stored grows,the overhead of RAID devices becomes a non-trivial efficiency issue.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a computingsystem in accordance with the invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the invention;

FIG. 3 is a schematic block diagram of an embodiment of a distributedstorage processing unit in accordance with the invention;

FIG. 4 is a schematic block diagram of an embodiment of a grid module inaccordance with the invention;

FIG. 5 is a diagram of an example embodiment of error coded data slicecreation in accordance with the invention;

FIG. 6A is a diagram illustrating an example of a plurality of receivedcoded matrices in accordance with the invention;

FIG. 6B is a diagram illustrating another example of a plurality ofreceived coded matrices in accordance with the invention;

FIG. 7A is a schematic block diagram of another embodiment of acomputing system in accordance with the invention;

FIG. 7B is a flowchart illustrating an example of receiving data inaccordance with the invention;

FIG. 8 is a diagram illustrating another example of a data encodingscheme in accordance with the invention;

FIG. 9 is a diagram illustrating an example of a data decoding scheme inaccordance with the invention;

FIG. 10 is a flowchart illustrating another example of receiving data inaccordance with the invention;

FIG. 11 is a flowchart illustrating an example of selecting a datastream in accordance with the invention;

FIG. 12A is a schematic block diagram of another embodiment of acomputing system in accordance with the invention;

FIG. 12B is a flowchart illustrating an example of relaying data inaccordance with the invention; and

FIG. 13 is a flowchart illustrating another example of receiving data inaccordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of a computing system 10 thatincludes one or more of a first type of user devices 12, one or more ofa second type of user devices 14, at least one distributed storage (DS)processing unit 16, at least one DS managing unit 18, at least onestorage integrity processing unit 20, and a distributed storage network(DSN) memory 22 coupled via a network 24. The network 24 may include oneor more wireless and/or wire lined communication systems; one or moreprivate intranet systems and/or public internet systems; and/or one ormore local area networks (LAN) and/or wide area networks (WAN).

The DSN memory 22 includes a plurality of distributed storage (DS) units36 for storing data of the system. Each of the DS units 36 includes aprocessing module and memory and may be located at a geographicallydifferent site than the other DS units (e.g., one in Chicago, one inMilwaukee, etc.).

Each of the user devices 12-14, the DS processing unit 16, the DSmanaging unit 18, and the storage integrity processing unit 20 may be aportable computing device (e.g., a social networking device, a gamingdevice, a cell phone, a smart phone, a personal digital assistant, adigital music player, a digital video player, a laptop computer, ahandheld computer, a video game controller, and/or any other portabledevice that includes a computing core) and/or a fixed computing device(e.g., a personal computer, a computer server, a cable set-top box, asatellite receiver, a television set, a printer, a fax machine, homeentertainment equipment, a video game console, and/or any type of homeor office computing equipment). Such a portable or fixed computingdevice includes a computing core 26 and one or more interfaces 30, 32,and/or 33. An embodiment of the computing core 26 will be described withreference to FIG. 2.

With respect to the interfaces, each of the interfaces 30, 32, and 33includes software and/or hardware to support one or more communicationlinks via the network 24 indirectly and/or directly. For example,interfaces 30 support a communication link (wired, wireless, direct, viaa LAN, via the network 24, etc.) between the first type of user device14 and the DS processing unit 16. As another example, DSN interface 32supports a plurality of communication links via the network 24 betweenthe DSN memory 22 and the DS processing unit 16, the first type of userdevice 12, and/or the storage integrity processing unit 20. As yetanother example, interface 33 supports a communication link between theDS managing unit 18 and any one of the other devices and/or units 12,14, 16, 20, and/or 22 via the network 24.

In general, and with respect to data storage, the system 10 supportsthree primary functions: distributed network data storage management,distributed data storage and retrieval, and data storage integrityverification. In accordance with these three primary functions, data canbe distributedly stored in a plurality of physically different locationsand subsequently retrieved in a reliable and secure manner regardless offailures of individual storage devices, failures of network equipment,the duration of storage, the amount of data being stored, attempts athacking the data, etc.

The DS managing unit 18 performs distributed network data storagemanagement functions, which include establishing distributed datastorage parameters, performing network operations, performing networkadministration, and/or performing network maintenance. The DS managingunit 18 establishes the distributed data storage parameters (e.g.,allocation of virtual DSN memory space, distributed storage parameters,security parameters, billing information, user profile information,etc.) for one or more of the user devices 12-14 (e.g., established forindividual devices, established for a user group of devices, establishedfor public access by the user devices, etc.). For example, the DSmanaging unit 18 coordinates the creation of a vault (e.g., a virtualmemory block) within the DSN memory 22 for a user device (for a group ofdevices, or for public access). The DS managing unit 18 also determinesthe distributed data storage parameters for the vault. In particular,the DS managing unit 18 determines a number of slices (e.g., the numberthat a data segment of a data file and/or data block is partitioned intofor distributed storage) and a read threshold value (e.g., the minimumnumber of slices required to reconstruct the data segment).

As another example, the DS managing module 18 creates and stores,locally or within the DSN memory 22, user profile information. The userprofile information includes one or more of authentication information,permissions, and/or the security parameters. The security parameters mayinclude one or more of encryption/decryption scheme, one or moreencryption keys, key generation scheme, and data encoding/decodingscheme.

As yet another example, the DS managing unit 18 creates billinginformation for a particular user, user group, vault access, publicvault access, etc. For instance, the DS managing unit 18 tracks thenumber of times a user accesses a private vault and/or public vaults,which can be used to generate a per-access bill. In another instance,the DS managing unit 18 tracks the amount of data stored and/orretrieved by a user device and/or a user group, which can be used togenerate a per-data-amount bill.

The DS managing unit 18 also performs network operations, networkadministration, and/or network maintenance. As at least part ofperforming the network operations and/or administration, the DS managingunit 18 monitors performance of the devices and/or units of the system10 for potential failures, determines the devices' and/or units'activation status, determines the devices' and/or units' loading, andany other system level operation that affects the performance level ofthe system 10. For example, the DS managing unit 18 receives andaggregates network management alarms, alerts, errors, statusinformation, performance information, and messages from the devices12-14 and/or the units 16, 20, 22. For example, the DS managing unit 18receives a simple network management protocol (SNMP) message regardingthe status of the DS processing unit 16.

The DS managing unit 18 performs the network maintenance by identifyingequipment within the system 10 that needs replacing, upgrading,repairing, and/or expanding. For example, the DS managing unit 18determines that the DSN memory 22 needs more DS units 36 or that one ormore of the DS units 36 needs updating.

The second primary function (i.e., distributed data storage andretrieval) begins and ends with a user device 12-14. For instance, if asecond type of user device 14 has a data file 38 and/or data block 40 tostore in the DSN memory 22, it sends the data file 38 and/or data block40 to the DS processing unit 16 via its interface 30. As will bedescribed in greater detail with reference to FIG. 2, the interface 30functions to mimic a conventional operating system (OS) file systeminterface (e.g., network file system (NFS), flash file system (FFS),disk file system (DFS), file transfer protocol (FTP), web-baseddistributed authoring and versioning (WebDAV), etc.) and/or a blockmemory interface (e.g., small computer system interface (SCSI), internetsmall computer system interface (iSCSI), etc.). In addition, theinterface 30 may attach a user identification code (ID) to the data file38 and/or data block 40.

The DS processing unit 16 receives the data file 38 and/or data block 40via its interface 30 and performs a distributed storage (DS) process 34thereon (e.g., an error coding dispersal storage function). The DSprocessing 34 begins by partitioning the data file 38 and/or data block40 into one or more data segments, which is represented as Y datasegments. For example, the DS processing 34 may partition the data file38 and/or data block 40 into a fixed byte size segment (e.g., 2¹ to2^(n) bytes, where n=>2) or a variable byte size (e.g., change byte sizefrom segment to segment, or from groups of segments to groups ofsegments, etc.).

For each of the Y data segments, the DS processing 34 error encodes(e.g., forward error correction (FEC), information dispersal algorithm,or error correction coding) and slices (or slices then error encodes)the data segment into a plurality of error coded (EC) data slices 42-48,which is represented as X slices per data segment. The number of slices(X) per segment, which corresponds to a number of pillars n, is set inaccordance with the distributed data storage parameters and the errorcoding scheme. For example, if a Reed-Solomon (or other FEC scheme) isused in an n/k system, then a data segment is divided into n slices,where k number of slices is needed to reconstruct the original data(i.e., k is the threshold). As a few specific examples, the n/k factormay be 5/3; 6/4; 8/6; 8/5; 16/10.

For each EC slice 42-48, the DS processing unit 16 creates a uniqueslice name and appends it to the corresponding EC slice 42-48. The slicename includes universal DSN memory addressing routing information (e.g.,virtual memory addresses in the DSN memory 22) and user-specificinformation (e.g., user ID, file name, data block identifier, etc.).

The DS processing unit 16 transmits the plurality of EC slices 42-48 toa plurality of DS units 36 of the DSN memory 22 via the DSN interface 32and the network 24. The DSN interface 32 formats each of the slices fortransmission via the network 24. For example, the DSN interface 32 mayutilize an internet protocol (e.g., TCP/IP, etc.) to packetize the ECslices 42-48 for transmission via the network 24.

The number of DS units 36 receiving the EC slices 42-48 is dependent onthe distributed data storage parameters established by the DS managingunit 18. For example, the DS managing unit 18 may indicate that eachslice is to be stored in a different DS unit 36. As another example, theDS managing unit 18 may indicate that like slice numbers of differentdata segments are to be stored in the same DS unit 36. For example, thefirst slice of each of the data segments is to be stored in a first DSunit 36, the second slice of each of the data segments is to be storedin a second DS unit 36, etc. In this manner, the data is encoded anddistributedly stored at physically diverse locations to improve datastorage integrity and security.

Each DS unit 36 that receives an EC slice 42-48 for storage translatesthe virtual DSN memory address of the slice into a local physicaladdress for storage. Accordingly, each DS unit 36 maintains a virtual tophysical memory mapping to assist in the storage and retrieval of data.

The first type of user device 12 performs a similar function to storedata in the DSN memory 22 with the exception that it includes the DSprocessing. As such, the device 12 encodes and slices the data fileand/or data block it has to store. The device then transmits the slices11 to the DSN memory via its DSN interface 32 and the network 24.

For a second type of user device 14 to retrieve a data file or datablock from memory, it issues a read command via its interface 30 to theDS processing unit 16. The DS processing unit 16 performs the DSprocessing 34 to identify the DS units 36 storing the slices of the datafile and/or data block based on the read command. The DS processing unit16 may also communicate with the DS managing unit 18 to verify that theuser device 14 is authorized to access the requested data.

Assuming that the user device is authorized to access the requesteddata, the DS processing unit 16 issues slice read commands to at least athreshold number of the DS units 36 storing the requested data (e.g., toat least 10 DS units for a 16/10 error coding scheme). Each of the DSunits 36 receiving the slice read command, verifies the command,accesses its virtual to physical memory mapping, retrieves the requestedslice, or slices, and transmits it to the DS processing unit 16.

Once the DS processing unit 16 has received a read threshold number ofslices for a data segment, it performs an error decoding function andde-slicing to reconstruct the data segment. When Y number of datasegments has been reconstructed, the DS processing unit 16 provides thedata file 38 and/or data block 40 to the user device 14. Note that thefirst type of user device 12 performs a similar process to retrieve adata file and/or data block.

The storage integrity processing unit 20 performs the third primaryfunction of data storage integrity verification. In general, the storageintegrity processing unit 20 periodically retrieves slices 45, and/orslice names, of a data file or data block of a user device to verifythat one or more slices have not been corrupted or lost (e.g., the DSunit failed). The retrieval process mimics the read process previouslydescribed.

If the storage integrity processing unit 20 determines that one or moreslices is corrupted or lost, it rebuilds the corrupted or lost slice(s)in accordance with the error coding scheme. The storage integrityprocessing unit 20 stores the rebuild slice, or slices, in theappropriate DS unit(s) 36 in a manner that mimics the write processpreviously described.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (IO)controller 56, a peripheral component interconnect (PCI) interface 58,an IO interface 60, at least one IO device interface module 62, a readonly memory (ROM) basic input output system (BIOS) 64, and one or morememory interface modules. The memory interface module(s) includes one ormore of a universal serial bus (USB) interface module 66, a host busadapter (HBA) interface module 68, a network interface module 70, aflash interface module 72, a hard drive interface module 74, and a DSNinterface module 76. Note the DSN interface module 76 and/or the networkinterface module 70 may function as the interface 30 of the user device14 of FIG. 1. Further note that the 10 device interface module 62 and/orthe memory interface modules may be collectively or individuallyreferred to as 10 ports.

FIG. 3 is a schematic block diagram of an embodiment of a dispersedstorage (DS) processing module 34 of user device 12 and/or of the DSprocessing unit 16. The DS processing module 34 includes a gatewaymodule 78, an access module 80, a grid module 82, and a storage module84. The DS processing module 34 may also include an interface 30 and theDSnet interface 32 or the interfaces 68 and/or 70 may be part of userdevice 12 or of the DS processing unit 16. The DS processing module 34may further include a bypass/feedback path between the storage module 84to the gateway module 78. Note that the modules 78-84 of the DSprocessing module 34 may be in a single unit or distributed acrossmultiple units.

In an example of storing data, the gateway module 78 receives anincoming data object that includes a user ID field 86, an object namefield 88, and the data object field 40 and may also receivecorresponding information that includes a process identifier (e.g., aninternal process/application ID), metadata, a file system directory, ablock number, a transaction message, a user device identity (ID), a dataobject identifier, a source name, and/or user information. The gatewaymodule 78 authenticates the user associated with the data object byverifying the user ID 86 with the DS managing unit 18 and/or anotherauthenticating unit.

When the user is authenticated, the gateway module 78 obtains userinformation from the management unit 18, the user device, and/or theother authenticating unit. The user information includes a vaultidentifier, operational parameters, and user attributes (e.g., userdata, billing information, etc.). A vault identifier identifies a vault,which is a virtual memory space that maps to a set of DS storage units36. For example, vault 1 (i.e., user 1's DSN memory space) includeseight DS storage units (X=8 wide) and vault 2 (i.e., user 2's DSN memoryspace) includes sixteen DS storage units (X=16 wide). The operationalparameters may include an error coding algorithm, the width n (number ofpillars X or slices per segment for this vault), a read threshold T, awrite threshold, an encryption algorithm, a slicing parameter, acompression algorithm, an integrity check method, caching settings,parallelism settings, and/or other parameters that may be used to accessthe DSN memory layer.

The gateway module 78 uses the user information to assign a source name35 to the data. For instance, the gateway module 78 determines thesource name 35 of the data object 40 based on the vault identifier andthe data object. For example, the source name may contain a fileidentifier (ID), a vault generation number, a reserved field, and avault identifier (ID). As another example, the gateway module 78 maygenerate the file ID based on a hash function of the data object 40.Note that the gateway module 78 may also perform message conversion,protocol conversion, electrical conversion, optical conversion, accesscontrol, user identification, user information retrieval, trafficmonitoring, statistics generation, configuration, management, and/orsource name determination.

The access module 80 receives the data object 40 and creates a series ofdata segments 1 through Y 90-92 in accordance with a data storageprotocol (e.g., file storage system, a block storage system, and/or anaggregated block storage system). The number of segments Y may be chosenor randomly assigned based on a selected segment size and the size ofthe data object. For example, if the number of segments is chosen to bea fixed number, then the size of the segments varies as a function ofthe size of the data object. For instance, if the data object is animage file of 4,194,304 eight bit bytes (e.g., 33,554,432 bits) and thenumber of segments Y=131,072, then each segment is 256 bits or 32 bytes.As another example, if segment size is fixed, then the number ofsegments Y varies based on the size of data object. For instance, if thedata object is an image file of 4,194,304 bytes and the fixed size ofeach segment is 4,096 bytes, then the number of segments Y=1,024. Notethat each segment is associated with the same source name.

The grid module 82 receives the data segments and may manipulate (e.g.,compression, encryption, cyclic redundancy check (CRC), etc.) each ofthe data segments before performing an error coding function of theerror coding dispersal storage function to produce a pre-manipulateddata segment. After manipulating a data segment, if applicable, the gridmodule 82 error encodes (e.g., Reed-Solomon, Convolution encoding,Trellis encoding, etc.) the data segment or manipulated data segmentinto X error coded data slices 42-44.

The value X, or the number of pillars (e.g., X=16), is chosen as aparameter of the error coding dispersal storage function. Otherparameters of the error coding dispersal function include a readthreshold T, a write threshold W, etc. The read threshold (e.g., T=10,when X=16) corresponds to the minimum number of error-free error codeddata slices required to reconstruct the data segment. In other words,the DS processing module 34 can compensate for X−T (e.g., 16−10=6)missing error coded data slices per data segment. The write threshold Wcorresponds to a minimum number of DS storage units that acknowledgeproper storage of their respective data slices before the DS processingmodule indicates proper storage of the encoded data segment. Note thatthe write threshold is greater than or equal to the read threshold for agiven number of pillars (X).

For each data slice of a data segment, the grid module 82 generates aunique slice name 37 and attaches it thereto. The slice name 37 includesa universal routing information field and a vault specific field and maybe 48 bytes (e.g., 24 bytes for each of the universal routinginformation field and the vault specific field). As illustrated, theuniversal routing information field includes a slice index, a vault ID,a vault generation, and a reserved field. The slice index is based onthe pillar number and the vault ID and, as such, is unique for eachpillar (e.g., slices of the same pillar for the same vault for anysegment will share the same slice index). The vault specific fieldincludes a data name, which includes a file ID and a segment number(e.g., a sequential numbering of data segments 1-Y of a simple dataobject or a data block number).

Prior to outputting the error coded data slices of a data segment, thegrid module may perform post-slice manipulation on the slices. Ifenabled, the manipulation includes slice level compression, encryption,CRC, addressing, tagging, and/or other manipulation to improve theeffectiveness of the computing system.

When the error coded data slices of a data segment are ready to beoutputted, the grid module 82 determines which of the DS storage units36 will store the EC data slices based on a dispersed storage memorymapping associated with the user's vault and/or DS storage unitattributes. The DS storage unit attributes may include availability,self-selection, performance history, link speed, link latency,ownership, available DSN memory, domain, cost, a prioritization scheme,a centralized selection message from another source, a lookup table,data ownership, and/or any other factor to optimize the operation of thecomputing system. Note that the number of DS storage units 36 is equalto or greater than the number of pillars (e.g., X) so that no more thanone error coded data slice of the same data segment is stored on thesame DS storage unit 36. Further note that EC data slices of the samepillar number but of different segments (e.g., EC data slice 1 of datasegment 1 and EC data slice 1 of data segment 2) may be stored on thesame or different DS storage units 36.

The storage module 84 performs an integrity check on the outboundencoded data slices and, when successful, identifies a plurality of DSstorage units based on information provided by the grid module 82. Thestorage module 84 then outputs the encoded data slices 1 through X ofeach segment 1 through Y to the DS storage units 36. Each of the DSstorage units 36 stores its EC data slice(s) and maintains a localvirtual DSN address to physical location table to convert the virtualDSN address of the EC data slice(s) into physical storage addresses.

In an example of a read operation, the user device 12 and/or 14 sends aread request to the DS processing unit 16, which authenticates therequest. When the request is authentic, the DS processing unit 16 sendsa read message to each of the DS storage units 36 storing slices of thedata object being read. The slices are received via the DSnet interface32 and processed by the storage module 84, which performs a parity checkand provides the slices to the grid module 82 when the parity check wassuccessful. The grid module 82 decodes the slices in accordance with theerror coding dispersal storage function to reconstruct the data segment.The access module 80 reconstructs the data object from the data segmentsand the gateway module 78 formats the data object for transmission tothe user device.

FIG. 4 is a schematic block diagram of an embodiment of a grid module 82that includes a control unit 73, a pre-slice manipulator 75, an encoder77, a slicer 79, a post-slice manipulator 81, a pre-slice de-manipulator83, a decoder 85, a de-slicer 87, and/or a post-slice de-manipulator 89.Note that the control unit 73 may be partially or completely external tothe grid module 82. For example, the control unit 73 may be part of thecomputing core at a remote location, part of a user device, part of theDS managing unit 18, or distributed amongst one or more DS storageunits.

In an example of write operation, the pre-slice manipulator 75 receivesa data segment 90-92 and a write instruction from an authorized userdevice. The pre-slice manipulator 75 determines if pre-manipulation ofthe data segment 90-92 is required and, if so, what type. The pre-slicemanipulator 75 may make the determination independently or based oninstructions from the control unit 73, where the determination is basedon a computing system-wide predetermination, a table lookup, vaultparameters associated with the user identification, the type of data,security requirements, available DSN memory, performance requirements,and/or other metadata.

Once a positive determination is made, the pre-slice manipulator 75manipulates the data segment 90-92 in accordance with the type ofmanipulation. For example, the type of manipulation may be compression(e.g., Lempel-Ziv-Welch, Huffman, Golomb, fractal, wavelet, etc.),signatures (e.g., Digital Signature Algorithm (DSA), Elliptic Curve DSA,Secure Hash Algorithm, etc.), watermarking, tagging, encryption (e.g.,Data Encryption Standard, Advanced Encryption Standard, etc.), addingmetadata (e.g., time/date stamping, user information, file type, etc.),cyclic redundancy check (e.g., CRC32), and/or other data manipulationsto produce the pre-manipulated data segment.

The encoder 77 encodes the pre-manipulated data segment 92 using aforward error correction (FEC) encoder (and/or other type of erasurecoding and/or error coding) to produce an encoded data segment 94. Theencoder 77 determines which forward error correction algorithm to usebased on a predetermination associated with the user's vault, a timebased algorithm, user direction, DS managing unit direction, controlunit direction, as a function of the data type, as a function of thedata segment 92 metadata, and/or any other factor to determine algorithmtype. The forward error correction algorithm may be Golay,Multidimensional parity, Reed-Solomon, Hamming, Bose Ray ChauduriHocquenghem (BCH), Cauchy-Reed-Solomon, or any other FEC encoder. Notethat the encoder 77 may use a different encoding algorithm for each datasegment 92, the same encoding algorithm for the data segments 92 of adata object, or a combination thereof.

The encoded data segment 94 is of greater size than the data segment 92by the overhead rate of the encoding algorithm by a factor of X/T, whereX is the width or number of slices, and T is the read threshold. In thisregard, the corresponding decoding process can accommodate at most X-Tmissing EC data slices and still recreate the data segment 92. Forexample, if X=16 and T=10, then the data segment 92 will be recoverableas long as 10 or more EC data slices per segment are not corrupted.

The slicer 79 transforms the encoded data segment 94 into EC data slicesin accordance with the slicing parameter from the vault for this userand/or data segment 92. For example, if the slicing parameter is X=16,then the slicer 79 slices each encoded data segment 94 into 16 encodedslices.

The post-slice manipulator 81 performs, if enabled, post-manipulation onthe encoded slices to produce the EC data slices. If enabled, thepost-slice manipulator 81 determines the type of post-manipulation,which may be based on a computing system-wide predetermination,parameters in the vault for this user, a table lookup, the useridentification, the type of data, security requirements, available DSNmemory, performance requirements, control unit directed, and/or othermetadata. Note that the type of post-slice manipulation may includeslice level compression, signatures, encryption, CRC, addressing,watermarking, tagging, adding metadata, and/or other manipulation toimprove the effectiveness of the computing system.

In an example of a read operation, the post-slice de-manipulator 89receives at least a read threshold number of EC data slices and performsthe inverse function of the post-slice manipulator 81 to produce aplurality of encoded slices. The de-slicer 87 de-slices the encodedslices to produce an encoded data segment 94. The decoder 85 performsthe inverse function of the encoder 77 to recapture the data segment90-92. The pre-slice de-manipulator 83 performs the inverse function ofthe pre-slice manipulator 75 to recapture the data segment 90-92.

FIG. 5 is a diagram of an example of slicing an encoded data segment 94by the slicer 79. In this example, the encoded data segment 94 includesthirty-two bits, but may include more or less bits. The slicer 79disperses the bits of the encoded data segment 94 across the EC dataslices in a pattern as shown. As such, each EC data slice does notinclude consecutive bits of the data segment 94 reducing the impact ofconsecutive bit failures on data recovery. For example, if EC data slice2 (which includes bits 1, 5, 9, 13, 17, 25, and 29) is unavailable(e.g., lost, inaccessible, or corrupted), the data segment can bereconstructed from the other EC data slices (e.g., 1, 3 and 4 for a readthreshold of 3 and a width of 4).

FIG. 6A is a diagram illustrating an example of a plurality of receivedcoded matrices 180. Each received coded matrix 180 of the plurality ofreceived coded matrices 180 is generated by a receiving entity receivingone or more coded value pairs (e.g., pairs of slices), extracting one ormore coded values from each coded value pair of the plurality of codedvalue pairs, and populating the received coded matrix 180 with the oneor more coded values in accordance with a decoding scheme. For example,the received coded matrix 180 is substantially the same as acorresponding coded matrix 122, when one or more coded value pairs arereceived without errors.

A decode threshold number of blocks (e.g., bytes when a block is onebyte) of each column of the received coded matrix 180 are decoded (e.g.,dispersed storage error decoded) to produce a corresponding column of acorresponding data matrix 114. For example, the decode threshold numberof bytes are matrix multiplied by an inverted square matrix (e.g., apillar width minus a threshold number of decode rows are eliminated toproduce a square matrix) of corresponding rows of an encoding matrix toproduce the corresponding column of the data matrix 114.

FIG. 6B is a diagram illustrating another example of a plurality ofreceived coded matrices 180. Each received coded matrix 180 of theplurality of received coded matrices 180 is generated by a receivingentity receiving one or more coded value pairs (e.g., pairs of slices),extracting one or more coded values from each coded value pair of theplurality of coded value pairs, and populating the received coded matrix180 with the one or more coded values in accordance with a decodingscheme. For example, the received coded matrix 180 is substantially notthe same as a corresponding coded matrix 122, when one or more codedvalue pairs are received with errors (e.g., one or more missing codedvalues due to communication errors). The receiving entity identifies oneor more missing coded values and sends a message to a sending entity tosend one or more additional coded values such that a decode thresholdnumber of coded value pairs per column of the received coded matrix 180are successfully received.

The receiving entity analyzes each column of the received coded matrix180 to determine how to generate a message for communicating to thesending entity. For example, the receiving entity sends a message to thesending entity indicating that no more coded values corresponding tocolumn 1 of a first received coded matrix 180 are required when bytes d11_1 through d1 1_5 were successfully received and validated (e.g.,calculated integrity information favorably compares to a receivedintegrity value). As another example, the receiving entity sends amessage to the sending entity indicating that one additional coded valuecorresponding to column 2 is required when bytes d2 1_1, d2 1_2, d2 1_4,and d2 1_5 were successfully received. Next, the receiving entityreceives byte d2 1_6 corresponding to column 2 to complete a decodethreshold number of coded values corresponding to column 2. Similarly,the receiving entity acquires bytes 6 and 7 of column 3 in a secondreceiving step when bytes 1 and 5 were missing from a first receivingstep. As yet another example, the receiving entity sends a message tothe sending entity indicating that at least one additional coded valuecorresponding to column 40k-1 is required since bytes 1-5 of column40k-1 produced a decoded data segment that failed an integrity test.Next, the receiving entity receives byte d1 20k_6 to utilize incombination with bytes 1-5 to attempt to decode a decode thresholdnumber of coded values that passes the integrity test. The method ofoperation of the receiving entity is discussed in greater detail withreference to FIGS. 7A-B.

FIG. 7A is a schematic block diagram of another embodiment of acomputing system that includes a computing device 190, a plurality ofdata sources 132, and a transmitting entity 192. The transmitting entity192 includes at least one of a sending user device 102 and a relay unit106. The computing device 190 includes a dispersed storage (DS) module194. The DS module 194 includes a receive module 196, a received codedmatrix module 198, a data matrix module 200, and a validity module 202.

The transmitting entity 192 time aligns a first data stream 146 and asecond data stream 148 segmenting the first and second data streams toproduce a first plurality of data segments corresponding to the firstdata stream 146 and a second plurality of data segments corresponding tothe second data stream 148. The first data stream may correspond to afirst recording of an environment and the second data stream maycorrespond to a second recording of the environment. The transmittingentity 192 transmits one or more pairs of coded values 154, wherein apair of coded values of the one or more pairs of coded values 154includes a coded value corresponding to one of the first plurality ofdata segments 206 and a coded value corresponding to one of the secondplurality of data segments 208.

The received module 196 receives the one or more pairs of coded values.The received coded matrix module 198 creates a received coded matrix 204from the one or more pairs of coded values 154. The received codedmatrix module 198 functions to create the received coded matrix 204 fromthe one or more pairs of coded values 154 by inputting pairs of codedvalues into the received coded matrix 204 in a sequential ordercorresponding to a time ordering of the one of the first plurality ofdata segments 206 and the one of the second plurality of data segments208 to maintain the time alignment of the first and second data streams146-148. The received coded matrix module 198 functions to create thereceived coded matrix 204 by, when triggered, determining whether thereceived coded matrix 204 includes a decode threshold number of pairs ofcoded values and when the received coded matrix 204 does not include thedecode threshold number of pairs of coded values generates a request 156for one or more additional pairs of coded values 158, sends the request156 to the transmitting entity 192, and receives the one or moreadditional pairs of coded values 158 from the transmitting entity 192.

The received coded matrix module 198 functions to determine whether thereceived coded matrix 204 includes the decode threshold number of pairsof coded values when triggered in a variety of ways. In a first way, thetrigger includes an expiration of a predetermined time period (e.g.,starting from reception of a first pair of coded values). In a secondway, the trigger includes receiving an indication from the transmittingentity 192 that at least a decode threshold number of the pairs of codedvalues have been transmitted (e.g., a message, a slice name associatedwith a coded value pair of the decode threshold number of pairs of codedvalues). In a third way, the trigger includes determining that the atleast the decode threshold number of the pairs of coded values have beentransmitted based on subsequent receptions of pairs of coded values fromother data segments of the first and second data streams 146-148. Thereceived coded matrix module 198 functions to generate the request 156for the one or more additional pairs of coded values by identifying anumber of additional pairs of coded values and generating the request156 for the number of additional pairs of coded values to include a listof slice names associated with the number of additional pairs of codedvalues.

When the received coded matrix 204 includes the decode threshold numberof pairs of coded values the data matrix module 200 generates a datamatrix from the received coded matrix 204 and an encoding matrix. Theencoding matrix includes at least one of a Reed-Solomon based encodingmatrix, an on-line coding based matrix, a Cauchy Reed-Solomon basedencoding matrix, a forward error correction based matrix, and an erasurecode based matrix. The data matrix module 200 functions to generate thedata matrix from the received coded matrix 204 and the encoding matrixby several steps for each column of the received coded matrix. In afirst step, the data matrix module 200 creates a received value matrixthat includes a decode threshold number of coded values of the column(e.g., delete rows not utilized, resulting matrix is one column wide bya decode threshold number of rows). In a second step, the data matrixmodule 200 creates a square encoding matrix based on corresponding rowsof the decode threshold number of coded values of the column (e.g.,delete rows not utilized). In a third step, the data matrix module 200inverts the square encoding matrix to produce an inverted squareencoding matrix. In a fourth step, the data matrix module 200 matrixmultiplies the received value matrix by the inverted square encodingmatrix to produce a corresponding column of the data matrix.

The data matrix module 200 reproduces the one of the first plurality ofdata segments 206 from a first plurality of data blocks of the datamatrix and reproduces the one of the second plurality of data segments208 from a second plurality of data blocks of the data matrix, whereinthe one of the first plurality of data segments 206 and the one of thesecond plurality of data segments 208 maintain the time alignment of thefirst and second data streams 146-148.

The validity module 202 determines whether the reproduced one of thefirst plurality of data segments 206 and the reproduced one of thesecond plurality of data segments 208 are valid (e.g., perform anintegrity test). When the reproduced one of the first plurality of datasegments 206 and the reproduced one of the second plurality of datasegments 208 are valid, the validity module 202 indicates to thetransmitting entity 192 that the received coded matrix includes thedecode threshold number of pairs of coded values. The indicating mayinclude one or more of outputting an indicator message 210 to thetransmitting entity 192 indicating that no more coded values arerequired and outputting data segments in a time synchronized fashion.When the reproduced one of the first plurality of data segments 206 andthe reproduce one of the second plurality of data segments 208 are notvalid, the validity module 202 indicates that the received coded matrix204 does not include the decode threshold number of pairs of codedvalues. The indicating may include outputting an indicator message 210to the transmitting entity 192 indicating that more coded values arerequired.

FIG. 7B is a flowchart illustrating an example of receiving data. Themethod begins at step 220 where a processing module (e.g., a dispersedstorage (DS) processing module of a receiving user device) receives oneor more pairs of coded values from a transmitting entity. A pair ofcoded values of the one or more pairs of coded values includes a codedvalue corresponding to one of a first plurality of data segments and acoded value corresponding to the one of a second plurality of datasegments. The transmitting entity obtains the one or more pairs of codedvalues in a variety of ways including generating, retrieving, andreceiving. When generating the one or more pairs of coded values, thetransmitting entity time aligns and segments each of a first data streamand a second data stream to produce the first plurality of data segmentscorresponding to the first data stream and the second plurality of datasegments corresponding to the second data stream. The first data streammay correspond to a first recording of an environment and the seconddata stream may correspond to a second recording of the environment whenthe first data stream corresponds to the first recording of theenvironment.

The method continues at step 222 wherein the processing module creates areceived coded matrix from the one or more pairs of coded values. Thecreating the received coded matrix from the one or more pairs of codedvalues includes inputting pairs of coded values into the received codedmatrix in a sequential order corresponding to a time ordering of the oneof the first plurality of data segments and the one of the secondplurality of data segments to maintain the time alignment of the firstand second data streams. The time ordering may be based on one or moreof time of receipt, time of transmission, time of generation, and aslice name correlation.

The creating the received coded matrix includes when triggered,determining whether the received coded matrix includes a decodethreshold number of pairs of coded values. The processing moduleacquires one or more additional pairs of coded values when the receivedcoded matrix does not include the decode threshold number of pairs ofcoded values. The acquiring includes generating a request for one ormore additional pairs of coded values, sending the request to atransmitting entity, and receiving the one or more additional pairs ofcoded values from the transmitting entity. The generating the requestfor the one or more additional pairs of coded values includesidentifying a number of additional pairs of coded values and generatingthe request for the number of additional pairs of coded values toinclude a list of slice names associated with the number of additionalpairs of coded values.

The determining whether the received coded matrix includes the decodethreshold number of pairs of coded values when triggered includes atleast one of several triggers. A first trigger includes expiration of apredetermined time period. A second trigger includes receiving anindication from the transmitting entity that at least a decode thresholdnumber of the pairs of coded values have been transmitted. A thirdtrigger includes determining that the at least a decode threshold numberof the pairs of coded values have been transmitted based on subsequentreceptions of pairs of coded values from other data segments of thefirst and second data streams.

When the received coded matrix includes the decode threshold number ofpairs of coded values, the method continues at step 224 where theprocessing module generates a data matrix from the received coded matrixand an encoding matrix. The encoding matrix includes at least one of aReed-Solomon based encoding matrix, an on-line coding based matrix, aCauchy Reed-Solomon based encoding matrix, a forward error correctionbased matrix, and an erasure code based matrix. The generating the datamatrix from the received coded matrix and the encoding matrix includes,several steps for each column of the received coded matrix. In a firststep, the processing module creates a received value matrix thatincludes a decode threshold number of coded values of the column. In asecond step, the processing module creates a square encoding matrixbased on corresponding rows of the decode threshold number of codedvalues of the column. In a third step, the processing module inverts thesquare encoding matrix to produce an inverted square encoding matrix. Ina fourth step, the processing module, matrix multiplies the receivedvalue matrix by the inverted square encoding matrix to produce acorresponding column of the data matrix. The method repeats for eachcolumn of the data matrix.

The method continues at step 226 wherein the processing modulereproduces the one of the first plurality of data segments from a firstplurality of data blocks of the data matrix. For example, the processingmodule extracts a column of the data matrix to produce the one of thefirst plurality of data segments when a data block is one byte. Themethod continues at step 228 where the processing module reproduces theone of the second plurality of data segments from a second plurality ofdata blocks of the data matrix, wherein the one of the first pluralityof data segments and the one of the second plurality of data segmentsmaintain the time alignment of the first and second data streams. Forexample, the processing module extracts an adjacent column to the columnof the data matrix to produce the one on the second plurality of datasegments.

The method continues at step 230 where the processing module determineswhether the reproduced one of the first plurality of data segments andthe reproduced one of the second plurality of data segments are valid.The processing module may perform a validation to include indicatingvalidity when a calculated integrity value is substantially the same asa retrieved integrity value for each of the data segments. The methodbranches to step 234 when the processing module determines that thereproduced one of the first plurality of data segments and thereproduced one of the second plurality of data segments are not valid(e.g., at least one is not valid). The method continues to step 232 whenthe processing module determines that the reproduced one of the firstplurality of data segments and the reproduced one of the secondplurality of data segments are valid.

When the reproduced one of the first plurality of data segments and thereproduced one of the second plurality of data segments are valid, themethod continues at step 232 where the processing module indicates tothe transmitting entity that the received coded matrix includes thedecode threshold number of pairs of coded values (e.g., generating andsending a message indicator). When the reproduced one of the firstplurality of data segments and the reproduced one of the secondplurality of data segments are not valid, the method continues at step234 where the processing module indicates that the received coded matrixdoes not include the decode threshold number of pairs of coded values.

FIG. 8 is a diagram illustrating another example of a data encodingscheme. The scheme includes data 1, data 2, data 3, an intermediatematrix 240, a column selector 242, a generator matrix 244, a dataselection 246, and a slice matrix tuner 48. The data 1-3 includes two ormore pluralities of data bytes. For example, data 1 includes 100,000bytes d1b1-d1b100k, data 2 includes 300,000 bytes d2b1-d2b100k, and data3 includes 100,000 bytes d3b1-d3b100k. The intermediate matrix 240includes matrix dimensions (e.g., number of rows, number of columns)based on a size of data 1-3 and error coding dispersal storage functionparameters (e.g., a decode threshold). For example, the intermediatematrix includes five rows and 100,000 columns, when the error codingdispersal storage function parameters includes a decode threshold offive and a data 1-3 size increment of 100,000 bytes each (e.g.,columns=data 1, 3 size). The intermediate matrix 240 includesalternating entries between data 1, data 2, and data 3 of sequentialdata bytes of data 1-3 in a row-by-row fashion. For example, row 1starts with data 1 and includes bytes d1b1-d1b100k, row 2 alternates todata 2 and includes bytes d2b1-d2b100k, row 2 continues with data 2 andincludes bytes d2b100k+1-d2b200k, row 3 continues with data 2 andincludes bytes d2b200k+1-d2b300k, and row 3 alternates to data 3 andincludes bytes d3b1-d3b100k. The alternating encoding scheme facilitatessubsequent time synchronization between data 1-3.

The generator matrix 244 includes matrix dimensions based on the errorcoding dispersal storage function parameters (e.g., the decodethreshold, a width). For example, the generator matrix 244 includes fivecolumns and eight rows when the decode threshold is five and the pillarwidth is eight. The generator matrix 244 includes entries in accordancewith an error coding dispersal storage function to produce encoded dataslices such that at least a decode threshold number of encoded dataslices may be utilized to subsequently reproduce the data.

The data selection 246 includes matrix dimensions of one by the decodethreshold (e.g., one by five when the decode threshold is five). Thecolumn selector 242 forms entries of the data selection 246 based onselecting data of each column of the intermediate matrix 240 one by one.For example, the column selector 242 selects a second selection ofcolumn 2 to include bytes d1b2, d2b2, d2b100k+2, d2b200k+2, and d3b2.

The slice matrix 248 includes matrix dimensions of a pillar width numberof rows (e.g., pillars) and a number of columns is substantially thesame as the number of columns of the intermediate matrix 240. The slicematrix 248 includes entries that form a pillar width number (e.g., anumber of rows of the slice matrix) of encoded data slices. The encodeddata slice of the width number of encoded data slices includes betweenone and a number of bytes substantially the same as the number ofcolumns of the intermediate matrix 240. For example, each encoded dataslice includes one byte when the slices correspond to one column of theslice matrix 248. As another example, each encoded data slice includes100,000 bytes when the slices correspond to all columns of the slicematrix 248.

In an example of operation, the column selector 242 selects one columnof the intermediate matrix 240 at a time to produce a data selection 246of a plurality of data selections. The generator matrix 244 ismultiplied by each data selection 246 of the plurality of dataselections to produce a corresponding column of a plurality of columnsof the slice matrix 248. For example, sm1_1=a*d1b1+b*d2b1+c*(d2b100k+1)+d*(d2b200k+1)+e*d3b1 when the columnselector 242 selects a first column. As another example, sm2_8=aj*d1b2+ak*d2b2+al*(d2b100k+2)+am*(d2b200k+2)+an*d3b2 when thecolumn selector 242 selects a second column.

Slices may be formed from the slice matrix 248 and transmitted to atleast one receiving entity to provide a reliable transmission of thedata 1-2. Slices are aligned by row and may include any number of bytesof the corresponding columns. For example, a pillar 1 (e.g., row 1)slice includes bytes sm 1_1, sm 2_1, sm 3_1, and sm 4_1 when four bytesmay be transmitted together as one slice. Slices from at least a decodethreshold number of rows are to be transmitted such that correspondingdata selections may be reproduced by decoding a decode threshold numberof bytes corresponding to a common column. More than a decode thresholdnumber of bytes per column may be transmitted when at least one of thedecode threshold number of bytes was not received by at least onereceiving entity. For example, bytes of column 1 corresponding to rows1-5 are transmitted as a first transmitting step and all bytes exceptthe byte of row 3 are received by the receiving entity. Any one of bytescorresponding to rows 3, 6-8 may be transmitted as a second transmittingstep to the receiving entity such that the receiving entity completesreceiving a decode threshold number of bytes corresponding to column 1.

FIG. 9 is a diagram illustrating an example of a data decoding schemefor decoding a received slice matrix 270 to produce an intermediatematrix 272. The received slice matrix 270 may be generated by areceiving entity receiving a plurality of slices from a sending entity,extracting one or more bytes from each slice of the plurality of slices,and populating the received slice matrix with the one or more bytes inaccordance with a decoding scheme. For example, the received slicematrix 270 is approximately the same as a slice matrix with theexception of missing bytes due to communication errors. The receivingentity identifies one or more missing bytes and sends a message to thesending entity to send one or more additional bytes per column such thata decode threshold number of bytes per column are successfully received.

The receiving entity analyzes each column of the received slice matrix270 to determine a message to send to the sending entity. For example,the receiving entity sends a message to the sending entity indicatingthat no more bytes corresponding to column 1 are required when bytes sm1_1 through sm 1_5 were successfully received and validated (e.g.,calculated integrity information favorably compares to sent integrityinformation). As another example, the receiving entity sends a messageto the sending entity indicating that one additional byte correspondingto column 2 is required when bytes sm 2_1, sm 2_2, sm 2_4, and sm 2_5were successfully received. Next, the receiving entity receives byte sm2_6 corresponding to column 2 to complete a decode threshold number ofbytes corresponding to column 2. Similarly, the receiving entityacquires bytes 6 and 7 of column 3 in a second receiving step when bytes1 and 5 were missing from a first receiving step. As yet anotherexample, the receiving entity sends a message to the sending entityindicating that at least one additional byte corresponding to column100k is required since bytes 1-5 of column 100k produced a decoded datasegment that failed an integrity test. Next, the receiving entityreceives byte sm 100k_6 to utilize in combination with bytes 1-5 toattempt to decode a data segment that passes the integrity test. Foreach column of the received slice matrix 270, a decode threshold numberof bytes are dispersed storage error decoded to produce a correspondingcolumn of the intermediate matrix 272. The method of operation of thereceiving entity is discussed in greater detail with reference to FIG.10.

FIG. 10 is a flowchart illustrating another example of receiving data.The method begins at step 274 where a processing module (e.g., areceiving entity such as a receiving user device dispersed storage (DS)processing) receives slices to produce received slices. The methodcontinues at step 276 where the processing module populates a receivedslice matrix with the received slices.

The method continues at step 278 where the processing module determineswhether a decode threshold number of slices should have been receivedfor a data selection. The data selection includes data bytes associatedwith two or more data streams rather than a data segment associated withone data stream. The determination may be based on one or more ofcomparing a count of a number of bytes per column to the decodethreshold number, comparing a count of a number of byte positions percolumn to the decode threshold number, received slice names, and adecode threshold number indicator. For example, processing moduledetermines that the decode threshold number of slices should have beenreceived for a data selection when a slice count indicates that thedecode threshold number of bytes was received. The method branches tostep 280 when the processing module determines that the decode thresholdnumber of slices should have been received. The method repeats back tostep 274 when the decode threshold number of slices should not have beenreceived so far.

The method continues at step 280 where the processing module determineswhether the decode threshold number of slices have been received for thedata selection. The processing module may determine that the decodethreshold number of slices have been received for the data selectionwhen a comparison of the number of received bytes of a common column ofthe received slice matrix to the decode threshold number is favorable(e.g., substantially the same). The method branches to step 284 when theprocessing module determines that the decode threshold number of sliceshave been received for the data selection. The method continues to step282 when the processing module determines that the decode thresholdnumber of slices have not been received for the data selection.

The method continues at step 282 where the processing module indicatesthat at least one more slice is required for the data segment. Theindication includes at least one of identifying which at least one moreslice is required based on which slices have been received so far andwhich slices have not been sent so far (e.g., higher order rows ofhigher order pillars) and sending a message to the sending entity thatincludes identification of at least one more required slice. Theindication may include identification of one more bytes that arerequired corresponding to each of the at least one more required slice.The method repeats back to step 274.

The method continues at step 284 where the processing module dispersedstorage error decodes the decode threshold number of slices to reproducea decoded data selection when the processing module determines that thedecode threshold number of slices have been received for the dataselection. The processing module decodes available bytes of a commoncolumn of the received slice matrix corresponding to the data selection.

The method continues at step 286 where the processing module determineswhether the decoded data segment passes an integrity test. For example,the processing module indicates passing the integrity test when acalculated integrity value (e.g., one of a hash digest of the dataselection, a cyclic redundancy check of the data selection, and a maskgenerating function output of the data selection) compares favorably(e.g., substantially the same) to a received integrity value associatedwith the data selection. The method loops back to step 282 when theprocessing module determines that the decoded data selection does notpass the integrity test. The method continues to step 288 when theprocessing module determines that the decoded data selection passes theintegrity test.

The method continues at step 288 where the processing module indicatesthat no more slices are required for the data selection. The indicationincludes at least one of sending a message to the sending entity thatindicates that no more slices are required for the column correspondingto the data selection, storing the decode threshold number of slices ina dispersed storage network (DSN) memory, dispersed storage errorencoding the data selection to reproduce a full set of slices, storingthe full set of slices in the DSN memory, and sending the full set ofslices to a remote user device.

The method continues at step 290 where the process module determineswhether another data selection is to be reproduced. The determinationmay be based on one or more of verifying that each column of thereceived slice matrix is associated with a corresponding data selectionthat passes the integrity test. The method repeats back to step 278 whenthe processing module determines that another data selection is to bereproduced. The method continues to step 300 when the processing moduledetermines that another data selection is not to be reproduced.

The method continues at step 300 where the processing module generatesan intermediate matrix based on a set of decoded data selections decodedfrom each column of the received slice matrix. For example, theprocessing module populates each column of the intermediate matrix witha corresponding data selection of the set of decoded data selections.The method continues at step 302 where the processing module generatestwo or more data streams from the intermediate matrix, wherein a datastream populates at least one row. For example, the processing modulepartitions a first row of the intermediate matrix to produce a firstdata stream; a second, third, and fourth row to produce a second datastream; and a fifth row to produce a third data stream.

FIG. 11 is a flowchart illustrating an example of selecting a datastream. The method begins at step 304 where a processing module (e.g., asending entity such as a sending user device dispersed storage (DS)processing) obtains user device to data stream affiliation information.The affiliation information includes at least one user device identifier(ID) and an associated data stream ID that the user device desires toreceive. The obtaining includes at least one of a lookup, a query, andreceiving the affiliation information.

The method continues at step 306 where the processing module obtainsuser device to communication path registration information. Theregistration information includes one or more of user device locationinformation, user device to wireless site registration information, atleast one user device ID, and a corresponding communication path ID,wherein a user device of the user device ID may receive communicationsvia a communication path associated with the communication path ID. Theobtaining includes at least one of a lookup, a query, and receiving theregistration information.

The method continues at step 308 where the processing module identifiesa user device to produce a user device ID based on the user device tocommunication path registration information. The identification includesat least one of identifying a next user device ID from a list of userdevice IDs, a lookup of the user device ID in a communication pathtable, accessing the communication path registration information.

The method continues at step 310 where the processing module identifiesat least one data stream of a plurality of data streams based on theuser device ID and the user device to data stream affiliationinformation. The identifying includes at least one of selecting a datastream ID associated with the user ID from the user device to datastream inflation information, a query, and receiving a data streamselection message.

The method continues at step 312 where the processing module determineswhether the at least one data stream is currently being communicated viaa communication path associated with user device based on the userdevice to communication path registration information. For example, theprocessing module determines that the at least one data stream is beingcommunicated one a data stream ID associated with the data stream is inan active data stream table associated with the communication path. Themethod branches to step 316 when the processing module determines thatthe at least one data stream is not being communicated. The methodcontinues to step 314 when the processing module determines that the atleast one data stream is being communicated. The method continues atstep 314 where the processing module identifies another user device(e.g., a next user device ID in a list of user device IDs associatedwith the communication path). The method branches back to step 308.

The method continues at step 316 where the processing module multiplexesthe at least one data stream with at least one other data stream togenerate an intermediate matrix when at least one other data stream isto be communicated via the communication path. The multiplexing includesat least one of creating a new intermediate matrix when no other datastreams exist and integrating the at least one data stream with the atleast one other data stream when the other data stream exists and theintermediate matrix already exists.

The method continues at step 318 where the processing module generatesat least a portion of a slice matrix based on the intermediate matrix.For example, the processing module generates at least enough columns ofthe slice matrix to transmit in a next broadcast transmission. Themethod continues at step 320 where the processing module outputs atleast a portion of the slice matrix to the user device via thecommunication path. The outputting includes sending at least a decodethreshold number of slices per column such that an integrity test of acorresponding decoded data selection/data segment by a receiving entitypasses an integrity test.

FIG. 12A is a schematic block diagram of another embodiment of acomputing system that includes a plurality of data sources 132, a firsttransmitting entity 322, a second transmitting entity 324, a computingdevice 326, and a requesting entity 330. The computing device 326includes a dispersed storage (DS) module 332. The DS module 332 includesa first coded matrix module 334, a second coded matrix module 336, a newcoded matrix module 338, and an output module 340.

A first data source 132 of the plurality of data sources 132 outputs afirst data stream 342 and a second data source 132 of the plurality ofdata sources 132 outputs a second data stream 344 to the firsttransmitting entity 322. A third data source 132 of the plurality ofdata sources 132 outputs a third data stream 346 and a fourth datasource 132 of the plurality of data sources 132 outputs a fourth datastream 348 to the second transmitting entity 324. Alternatively, atleast one of the first transmitting entity 322 and the secondtransmitting entity 324 receives the first data stream 342, the seconddata stream 344, the third data stream 346, and the fourth data stream348 from the plurality of data sources 132. The first data stream maycorrespond to a first recording of an environment from a first recordingdevice (e.g., the first transmitting entity 322). The second data streammay correspond to a second recording of the environment from the firstrecording device. The third data stream may correspond to a thirdrecording of the environment from a second recording device (e.g., thesecond transmitting entity 324). The fourth data stream may correspondto a fourth recording of the environment from the second recordingdevice.

The first transmitting entity 322 segments the first data stream 342 andthe second data stream 344 to produce a first data segment of the firstdata stream 342 and a first data segment of the second data stream 344.The first transmitting entity 322 divides the first data segment of thefirst data stream 342 to produce a first plurality of data blocks. Thefirst transmitting entity 322 divides the first data segment of thesecond data stream 344 to produce a second plurality of data blocks. Thefirst transmitting entity 322 creates a first data matrix utilizing thefirst and second plurality of data blocks. The first transmitting entity322 generates a first coded matrix 334 from the data matrix and anencoding matrix (e.g., matrix multiplying). The encoding matrix includesat least one of a Reed-Solomon based encoding matrix, an on-line codingbased matrix, a Cauchy Reed-Solomon based encoding matrix, a forwarderror correction based matrix, and an erasure code based matrix. Thefirst transmitting entity 322 outputs a first plurality of pairs ofcoded values 350 corresponding to the first data segments of the firstdata stream 342 and the second data stream 344 by extracting the firstplurality of pairs of coded values 350 from adjacent columns of thefirst coded matrix 358.

The second transmitting entity 324 segments the third data stream 346and the fourth data stream 348 to produce a first data segment of thethird data stream 346 and a first data segment of the fourth data stream348. The second transmitting entity 324 divides the first data segmentof the third data stream 346 to produce a third plurality of datablocks. The second transmitting entity 324 divides the first datasegment of the fourth data stream 348 to produce a fourth plurality ofdata blocks. The second transmitting entity 324 creates a second datamatrix utilizing the third and fourth plurality of data blocks. Thesecond transmitting entity 324 generates a second coded matrix 360 fromthe second data matrix and the encoding matrix. The second transmittingentity 324 outputs a second plurality of pairs of coded values 352corresponding to the first data segments of the third data stream 346and the fourth data stream 348 by extracting the second plurality ofpairs of coded values 352 from adjacent columns of the second codedmatrix 360.

The first coded matrix module 334 receives (e.g., from one of the firsttransmitting entity 322 and the second transmitting entity 324) thefirst coded matrix 358 that includes the first plurality of pairs ofcoded values 350 corresponding to first data segments of the first datastream 342 and the second data stream 344. A pair of coded values of thefirst plurality of pairs of coded values 350 includes a first codedvalue corresponding to the first data segment of the first data stream342 and a second coded value corresponding to the first data segment ofthe second data stream 344.

The second coded matrix module 336 receives the second coded matrix 360that includes the second plurality of pairs of coded values 352corresponding to first data segments of the third data stream 346 andthe fourth data stream 348. A pair of coded values of the secondplurality of pairs of coded values 352 includes a third coded valuecorresponding to the first data segment of the third data stream 346 anda fourth coded value corresponding to the first data segment of thefourth data stream 348. The first data segments of the first, second,third, and fourth data streams are time aligned based on at least one ofsimultaneous encoding, simultaneous transmission, time alignment bycoded value identifier, time alignment by a slice name, coded valuepairing, and a timestamp.

The new coded matrix module 338 may determine to generate a new codedmatrix 354 based on one or more of a variety of ways. In a first way,the new coded matrix module 338 generates the new coded matrix 354 basedon a request 356 from the requesting entity 330 (e.g., a request for twoor more data streams). In a second way, the new coded matrix module 338generates the new coded matrix 354 based on capabilities of therequesting entity 330 (e.g., communications path bandwidth to therequesting entity, decoding capability of the requesting entity). In athird way, the new coded matrix module 338 generates the new codedmatrix 354 based on a predetermination (e.g., fixed data streamselections). In a fourth way, the new coded matrix module 338 generatesthe new coded matrix 354 based on a request from at least one of thefirst transmitting entity 322 and the second transmitting entity 324.The new coded matrix module 338 generates the new coded matrix 354 toinclude a plurality of groups of selected coded values 362. One of theplurality of groups of selected coded values includes at least two ofthe first, second, third, and fourth coded values. For example, the newcoded matrix module 338 generates the new coded matrix 354 to include aplurality of groups of selected coded values that includes coded valuesassociated with the second data stream 344 and the third data stream 346when the request 356 indicates to send a plurality of groups of selectedcoded values 362 associated with the second data stream 344 and thethird data stream 346.

The output module 340 outputs the plurality of groups of selected codedvalues 362 to the requesting entity 330 in a manner to maintain the timealignment of the first data segments of the first, second, third, andfourth data streams (e.g., coded values of pairs of coded values are intime alignment). The output module 340 determines time alignment of thefirst data segments of the first, second, third, and fourth data streamsin a variety of ways. In a first way, the output module 340 determinestime alignment by interpreting time-stamp information (e.g., time-stampper coded value). In a second way, the output module 340 determines timealignment by interpreting naming information of the first data segmentof the first, second, third, and fourth data streams. The naminginformation includes at least one of slice names, coded valueidentifiers, group names, and sequence numbers.

When the requesting entity 330 requires more coded values, the new codedmatrix module 338 receives a request 364 from the requesting entity forone or more additional groups of selected coded values (e.g., by datastream identifier, by coded value names, by group ID) and generates theone or more additional groups of selected coded values 366 utilizing thefirst and second coded matrixes 358-360. When the one or more additionalgroups of selected coded values 366 are not available within the newcoded matrix 354, the new coded matrix module 338 rebuilds the one ormore additional groups of selected coded values 366. The rebuildingincludes decoding a decode threshold number of associated groups ofselected coded values to produce a data segment and encoding the datasegment to produce the one or more additional groups of selected codedvalues. The output module 340 outputs the one or more additional groupsof selected coded values 366 to the requesting entity 330.

FIG. 12B is a flowchart illustrating an example of relaying data. Themethod begins at step 370 where a processing module (e.g., of adispersed storage (DS) processing module of a relay unit) receives afirst coded matrix that includes a first plurality of pairs of codedvalues corresponding to first data segments of a first data stream and asecond data stream. A pair of coded values of the first plurality ofpairs of coded values includes a first coded value corresponding to thefirst data segment of the first data stream and a second coded valuecorresponding to the first data segment of the second data stream. Thefirst data segment of the first data stream is divided into a firstplurality of data blocks and the first data segment of the second datastream is divided into a second plurality of data blocks, wherein thefirst and second plurality of data blocks create a first data matrix.The first coded matrix is generated from the data matrix and an encodingmatrix. The first data stream may correspond to a first recording of anenvironment from a first recording device. The second data stream maycorrespond to a second recording of the environment from the firstrecording device.

The method continues at step 372 or the processing module receives asecond coded matrix that includes a second plurality of pairs of codedvalues corresponding to first data segments of a third data stream and afourth data stream. A pair of coded values of the second plurality ofpairs of coded values includes a third coded value corresponding to thefirst data segment of the third data stream and a fourth coded valuecorresponding to the first data segment of the fourth data stream. Thefirst data segment of the third data stream is divided into a thirdplurality of data blocks and the first data segment of the fourth datastream is divided into a fourth plurality of data blocks, wherein thethird and fourth plurality of data blocks create a second data matrix.The second coded matrix is generated from the second data matrix and theencoding matrix.

The third data stream may correspond to a third recording of theenvironment from a second recording device. The fourth data stream maycorrespond to a fourth recording of the environment from the secondrecording device. The first data segments of the first, second, third,and fourth data streams may be time aligned. The processing module maydetermine the time alignment of the first data segments of the first,second, third, and fourth data streams by at least one of interpretingtime-stamp information, interpreting naming information of the firstdata segment of the first, second, third, and fourth data streams.

The method continues at step 374 where the processing module generates anew coded matrix to include a plurality of groups of selected codedvalues. One of the plurality of groups of selected coded values includesat least two of the first, second, third, and fourth coded values. Theprocessing module may generate the new coded matrix based on at leastone of a request from the requesting entity and capabilities of therequesting entity. The method continues at step 376 where the processingmodule outputs the plurality of groups of selected coded values to arequesting entity in a manner to maintain the time alignment of thefirst data segments of the first, second, third, and fourth datastreams.

The method continues at step 378 where the processing module receives arequest from the requesting entity for one or more additional groups ofselected coded values. The method continues at step 380 where theprocessing module generates the one or more additional groups ofselected coded values utilizing the first and second coded matrixes. Themethod continues at step 382 where the processing module outputs the oneor more additional groups of selected coded values to the requestingentity.

FIG. 13 is a flowchart illustrating another example of receiving data,which include similar steps to FIG. 10. The method begins with steps274-276 of FIG. 10 where a processing module (e.g., a receiving entitysuch as a receiving user device dispersed storage (DS) processing)receives slices to produce received slices and populates a receivedslice matrix based on the received slices. The method continues at step388 where the processing module identifies desired columns of thereceived slice matrix based on a desired data stream. The identifyingmay be based on one or more of an encoding scheme, a decoding scheme, anumber of data streams, a desired data stream indicator, a data streamposition indicator, and a message.

The method continues at step 390 where the processing module determineswhether the decode threshold number of slices per desired column of thereceived slice matrix pass an integrity test. The processing moduleindicates passing the integrity test when a calculated integrity valueof a decoded data segment/selection (e.g., dispersed storage everydecoded from the decode threshold number of slices of a desired column)compares favorably to a received integrity value of the datasegment/selection. The method branches to step 392 when the processingmodule determines that the decode threshold number of slices per desiredcolumn passes the integrity test. The method loops back to step 274 ofFIG. 7 to receive more slices when the processing module determines thatthe decode threshold number of slices per desired column fails theintegrity test.

The method continues at step 392 where the processing module dispersedstorage error decodes each decode threshold number of slices per desiredcolumn to produce corresponding decoded data selections reproducing atleast a portion of a slice matrix. As such, undesired columns (e.g.,corresponding only to one or more undesired data streams) are skipped.The method continues at step 394 where the processing module generatesan intermediate matrix based on the at least a portion of the slicematrix. The processing module generates the intermediate matrix bypopulating the intermediate matrix with the decoded data selections inaccordance with at least one of a data encoding scheme, a datamultiplexing scheme, and a data decoding scheme. The method continues atstep 396 where the processing module extracts the desired data streamfrom the intermediate matrix. The extracting may be based on one or moreof the desired data stream indicator, the data multiplexing scheme, apredetermination, and a de-multiplexing instruction.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

As may also be used herein, the terms “processing module”, “module”,“processing circuit”, and/or “processing unit” may be a singleprocessing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, and/or processing unit may have anassociated memory and/or an integrated memory element, which may be asingle memory device, a plurality of memory devices, and/or embeddedcircuitry of the processing module, module, processing circuit, and/orprocessing unit. Such a memory device may be a read-only memory, randomaccess memory, volatile memory, non-volatile memory, static memory,dynamic memory, flash memory, cache memory, and/or any device thatstores digital information. Note that if the processing module, module,processing circuit, and/or processing unit includes more than oneprocessing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

The present invention has been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention. Further, theboundaries of these functional building blocks have been arbitrarilydefined for convenience of description. Alternate boundaries could bedefined as long as the certain significant functions are appropriatelyperformed. Similarly, flow diagram blocks may also have been arbitrarilydefined herein to illustrate certain significant functionality. To theextent used, the flow diagram block boundaries and sequence could havebeen defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claimed invention. One of average skill in the artwill also recognize that the functional building blocks, and otherillustrative blocks, modules and components herein, can be implementedas illustrated or by discrete components, application specificintegrated circuits, processors executing appropriate software and thelike or any combination thereof.

The present invention may have also been described, at least in part, interms of one or more embodiments. An embodiment of the present inventionis used herein to illustrate the present invention, an aspect thereof, afeature thereof, a concept thereof, and/or an example thereof. Aphysical embodiment of an apparatus, an article of manufacture, amachine, and/or of a process that embodies the present invention mayinclude one or more of the aspects, features, concepts, examples, etc.described with reference to one or more of the embodiments discussedherein. Further, from figure to figure, the embodiments may incorporatethe same or similarly named functions, steps, modules, etc. that may usethe same or different reference numbers and, as such, the functions,steps, modules, etc. may be the same or similar functions, steps,modules, etc. or different ones.

While the transistors in the above described figure(s) is/are shown asfield effect transistors (FETs), as one of ordinary skill in the artwill appreciate, the transistors may be implemented using any type oftransistor structure including, but not limited to, bipolar, metal oxidesemiconductor field effect transistors (MOSFET), N-well transistors,P-well transistors, enhancement mode, depletion mode, and zero voltagethreshold (VT) transistors.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of the various embodimentsof the present invention. A module includes a functional block that isimplemented via hardware to perform one or module functions such as theprocessing of one or more input signals to produce one or more outputsignals. The hardware that implements the module may itself operate inconjunction software, and/or firmware. As used herein, a module maycontain one or more sub-modules that themselves are modules.

While particular combinations of various functions and features of thepresent invention have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent invention is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A method comprises: receiving one or more pairsof coded values, wherein a pair of coded values of the one or more pairsof coded values includes a coded value corresponding to one of a firstplurality of data segments and a coded value corresponding to the one ofa second plurality of data segments and wherein each of a first datastream and a second data stream are segmented to produce the firstplurality of data segments corresponding to the first data stream andthe second plurality of data segments corresponding to the second datastream; creating a received coded matrix from the one or more pairs ofcoded values; generating a first data matrix from the received codedmatrix and an encoding matrix; identifying a first plurality of datablocks of the first data matrix that correspond to the first datastream; determining whether the first plurality of data blocks includesa decode threshold number of pairs of coded values; and when the firstplurality of data blocks includes a decode threshold number of pairs ofcoded values, determining whether the decode threshold number of pairsof coded values are valid; decoding the decode threshold number of pairsof coded values; generating a second data matrix; and extracting thefirst data stream from the second data matrix.
 2. The method of claim 1further comprises: identifying a second plurality of data blocks of thefirst data matrix that correspond to the second data stream; determiningwhether the second plurality of data blocks includes a decode thresholdnumber of pairs of coded values; and when the second plurality of datablocks includes a decode threshold number of pairs of coded values,determining whether the decode threshold number of pairs of coded valuesare valid; decoding the decode threshold number of pairs of coded valuesto generating a third data matrix; and extracting the second data streamfrom the third data matrix.
 3. The method of claim 1, wherein theidentifying a first plurality of data blocks of the first data matrixthat correspond to the first data stream is based on at least one of anencoding scheme, a decoding scheme, a number of data streams, a desireddata stream indicator, a data stream position indicator, and a message.4. The method of claim 1, wherein the first data matrix is an encodeddata slice matrix.
 5. The method of claim 4, wherein the second datamatrix is at least a portion of an encoded data slice matrix.
 6. Themethod of claim 1 further comprises: generating a fourth matrix beforeextracting the first data stream from the second data matrix, whereinthe fourth matrix is based on at least a portion of the second matrix.7. The method of claim 1, wherein the determining whether the decodethreshold number of pairs of coded values are valid is based on whethera value calculated from a decoded data selection associated with thefirst data block compares favorably to a received value for the firstdata block.
 8. A computing device comprises: a network interface;memory; and a processing module operably coupled to the networkinterface and the memory, wherein the processing module is operable to:receive one or more pairs of coded values, wherein a pair of codedvalues of the one or more pairs of coded values includes a coded valuecorresponding to one of a first plurality of data segments and a codedvalue corresponding to the one of a second plurality of data segmentsand wherein each of a first data stream and a second data stream aresegmented to produce the first plurality of data segments correspondingto the first data stream and the second plurality of data segmentscorresponding to the second data stream; create a received coded matrixfrom the one or more pairs of coded values; generate a first data matrixfrom the received coded matrix and an encoding matrix; identify a firstplurality of data blocks of the first data matrix that correspond to thefirst data stream; determine whether the first plurality of data blocksincludes a decode threshold number of pairs of coded values; and whenthe first plurality of data blocks includes a decode threshold number ofpairs of coded values, determine whether the decode threshold number ofpairs of coded values are valid; decode the decode threshold number ofpairs of coded values; generate a second data matrix; and extract thefirst data stream from the second data matrix.
 9. The computing deviceof claim 8, wherein the processing module is further operable to:identify a second plurality of data blocks of the first data matrix thatcorrespond to the second data stream; determine whether the secondplurality of data blocks includes a decode threshold number of pairs ofcoded values; and when the second plurality of data blocks includes adecode threshold number of pairs of coded values, determine whether thedecode threshold number of pairs of coded values are valid; decode thedecode threshold number of pairs of coded values to generate a thirddata matrix; and extract the second data stream from the third datamatrix.
 10. The computing device of claim 8, wherein the first pluralityof data blocks of the first data matrix that correspond to the firstdata stream is identified based on at least one of an encoding scheme, adecoding scheme, a number of data streams, a desired data streamindicator, a data stream position indicator, and a message.
 11. Thecomputing device of claim 8, wherein, the first data matrix is anencoded data slice matrix.
 12. The computing device of claim 8, whereinthe second data matrix is at least a portion of an encoded data slicematrix.
 13. The computing device of claim 10 further comprises: generatea fourth matrix before extracting the first data stream from the seconddata matrix, wherein the fourth matrix is based on at least a portion ofthe second matrix.
 14. The computing device of claim 8, wherein thedetermine whether the decode threshold number of pairs of coded valuesare valid is based on whether a value calculated from a decoded dataselection associated with the first data block compares favorably to areceived value for the first data block.
 15. A non-transitory computerreadable storage device comprises: a first memory section that storesoperational instruction that, when executed by a computing device,causes the computing device to: receive one or more pairs of codedvalues, wherein a pair of coded values of the one or more pairs of codedvalues includes a coded value corresponding to one of a first pluralityof data segments and a coded value corresponding to the one of a secondplurality of data segments and wherein each of a first data stream and asecond data stream are segmented to produce the first plurality of datasegments corresponding to the first data stream and the second pluralityof data segments corresponding to the second data stream; a secondmemory section that stores operational instruction that, when executedby the computing device, causes the computing device to: create areceived coded matrix from the one or more pairs of coded values; andgenerate a first data matrix from the received coded matrix and anencoding matrix; a third memory section that stores operationalinstruction that, when executed by the computing device, causes thecomputing device to: identify a first plurality of data blocks of thefirst data matrix that correspond to the first data stream; determinewhether the first plurality of data blocks includes a decode thresholdnumber of pairs of coded values; and when the first plurality of datablocks includes a decode threshold number of pairs of coded values,determine whether the decode threshold number of pairs of coded valuesare valid; decode the decode threshold number of pairs of coded values;generate a second data matrix; and extract the first data stream fromthe second data matrix.
 16. The non-transitory computer readable storagedevice of claim 15, wherein the third memory section further storesoperational instruction that, when executed by the computing device,causes the computing device to: identify a second plurality of datablocks of the first data matrix that correspond to the second datastream; determine whether the second plurality of data blocks includes adecode threshold number of pairs of coded values; and when the secondplurality of data blocks includes a decode threshold number of pairs ofcoded values, determine whether the decode threshold number of pairs ofcoded values are valid; decode the decode threshold number of pairs ofcoded values to generate a third data matrix; and extract the seconddata stream from the third data matrix.
 17. The non-transitory computerreadable storage device of claim 15, wherein the third memory sectionfurther stores operational instruction that, when executed by thecomputing device, causes the computing device to: generate the firstdata matrix based on at least one of an encoding scheme, a decodingscheme, a number of data streams, a desired data stream indicator, adata stream position indicator, and a message.
 18. The non-transitorycomputer readable storage device of claim 15, wherein the third memorysection further stores operational instruction that, when executed bythe computing device, causes the computing device to: generate a fourthmatrix before extracting the first data stream from the second datamatrix, wherein the fourth matrix is based on at least a portion of thesecond matrix.
 19. The non-transitory computer readable storage deviceof claim 15, wherein the third memory section further stores operationalinstruction that, when executed by the computing device, causes thecomputing device to: determine whether the decode threshold number ofpairs of coded values are valid based on whether a value calculated froma decoded data selection associated with the first data block comparesfavorably to a received value for the first data block.